Apparatus for ironing insulated coils



Nov. 2, 1954 l A. BRAM APPARATUS FOR IRONING INSULATED COILS Filed June 21, 1951 M J Y, m.

ATTORNEYS INVENTOR elements and the straight coil nd element.

AlfredBriim, Schlieren, n... Zurich, Switzerland, as

, signor to Micafil A .-G., Zurich, Switzerland Application June '21, 1951, Serial No. 232,744 Claims priority, application Switzerland June 23, 1950 8 Claims. (Cl. 1541) Ironing devices by means of which insulating material is pressed on to the straight portions of the conductor coils and windings of electrical machines and apparatus prior to their installation in the machine or apparatus are known, where the ironing device is made to rotate around the stationary coil part. Such ironing devices generally consist of a pair of heated tubular or rail-shaped ironing elements which are applied to the straight coil portion with a constant pressure which is produced by springs which press the irons on to the conductorpart that is to be ironed.

In order to achieve closer contact between the ironing portion, especially in the case of long and large coils where the bars often tend to twist and sag or have an irregular cross-section, it has already been proposed to employ resilient annular bands instead of the rigid pair of ironing elements, these bands being fixed to two supports of suitable length. These bands can furthermore be mounted on helical springs or similar elements the length of which can be varied, so that the ironing elements can be adjusted within certain limits to suit the length of the coil.

This adjustment of the length is, however, very restricted for the following reason. The bands of one ironing element are displaced axially with respect to the bands of the other ironing element, so that the bands of the first element bridge over the gaps between the bands of the sec- This overlapping of the bands is necessary in order to be able to iron the entire coil length in a uniform manner. Since, however, the possible variation in the length of the ironing element depends upon the amount of free space available between the bands, the aforementioned overlap restricts the adjustment which is possible.

The object of the invention is to provide a mechanical ironing device for pressing insulating material on to the straight portions of the coils and windings of electrical machines and apparatus prior to their installation in the machine or apparatus, the ironing elements consisting of two opposing rows of flexible bands which are mutually displaced in the axial direction, and where the ironing elements rotate about the straight conductor portion and can be adjusted with sufiicient accuracy to suit any length of coil. According to the invention this is achieved by fixing the ironing elements to the internal surface of a rotatable drum which by means of adding at least one coaxial ring element with internally arranged ring bands can be enlarged axially to any desirable extent, the ends of the drum being closed by covers. 7

A constructional example of the invention is illustrated in the accompanying drawing where Fig. 1 shows an ironing device in horizontal longitudinal section, whilst Fig. 2 shows a cross-sectional view of the same device.

Fig. 3 is a view similar to Fig. 2 illustrating a modified construction wherein the ironing elements are heated by internally located electrical heating resistances, and Fig. 4 is a view similar to Fig. 3 showing a still further modification wherein the ironing elements themselves are constructed as electrical resistances to produce their own heating.

The ironing device consists of a drum 3 which is provided with coaxial cylindrical bearing surfaces 9 and is rotatably mounted in a stand 11. On the inside of the drum 3 opposing ironing elements consisting of the flexible band rings 1 and 2 respectively are so arranged that the band rings 2 of the one element lie opposite to the gaps 6 between the band rings 1 of the other element and States PMWQ "ic 1 vice versa," At'least one further coaxial ring element can be fixedby' means of bolts 8 to one or both ends of .ironing device is enlarged in the direction of its are also equipped with the drum 3 (in the constructional example illustrated in the drawing there are three such additional elements added to..eac h end' of the drum). By this means the 7 axis of rotation. These rmg'elements 5 staggered opposing band ringsl and 2. Bothends'of the drum are closed by means of covers 4.

In order that the coil portion which has to be ironed can be introduced into the ironing device and also removed again afterwards, the central drum 3 as well as the additional ring elements 5 at both ends and the stand 11 have each to be provided with a slot-like opening, all these openings 7 being located in the same axial plane. The stand 11 is provided with a bracket 14 which carries a rod 17. Two supporting arms 15 are mounted on this rod 17 in an adjustable manner and serve to support the coil 16.

Between the bearing surfaces 9 on the outside of the drum 3 teeth 10 are provided which are in engagement With the toothed driving wheels 12 which are rotatably mounted in the stand 11 and are caused to rotate in any known manner.

The ironing elements 1 and 2 in the embodiment of the invention illustrated in Figs. 1 and 2 are heated by means of an elongated gas burner 20 located externally of the drum 3 and ring elements 5, the burner extending parallel to the axis of rotation and being provided with a plurality of burner nozzles or ports21 opening laterally to the surface of the drum and ring elements.

The ironing elements 1' and 2 can also be heated by electrical heating resistances 18 arranged inside the elements as shown in Fig. 3 which by means of conventional slip rings and brushes, not shown, are connected to a suitable source of electric current. The band rings 1", 2" can of course also be constructed as shown in Fig. 4 to act as electrical heating elements, leads 19 being connected to opposite ends of the open rings for connection to a source of voltage indicated by the conventional symbols.

With the device described above it is possible to iron any length of conductor within very wide limits, the minimum length being given by the axial length of the drum 3.

I claim:

1. In a device for mechanically ironing insulating material onto the straight conductor portions of preformed windings, coils and the like of electrical machines prior to their installation in the machine, the combination comprising a drum having a pair of confronting rows of mutually displaced flexible bands secured to the internal surface of said drum and adapted to press against said straight conductor portion,'said drum being constituted by an assembly of axial drum sections joined coaxially and being detachable from one another to thereby permit a change in the length of said rows of bands, and means for rotating said drum to thereby rotate said bands about said straight conductor portions.

2. In a device for mechanically ironing insulating material onto the straight conductor portions of preformed windings, coils and the like of electrical machines prior to their installation in the machine, the combination comprising a drum having a pair of confronting rows of mutually displaced flexible bands secured to the internal surface of said drum and adapted to press against the said straight conductor portions, and means for rotating said drum to thereby rotate said bands about said straight conductor portions, said drum being constituted by a main portion of substantial axial length carrying a pinrality of the said flexible bands of each row and at least one ring element of comparatively shorter axial length, said ring element having others of said flexible bands secured to the internal surface thereof, means detachably securing said ring element to and coaxially with the main portion of said drum, and a cover member closing each end of said drum.

3. An ironing device as defined in claim 2 and which further includes a stand upon which said drum is mounted, and the means for rotating said drum includes toothed driving wheels journalled on said stand and meshed with an external toothed ring on the main portion of said drum.

4. An ironing device as defined in claim 2 wherein said Patented Nov. ,2, 1954- drum and end covers therefor areprovided with aligned slot-like radial openings through which the conductor to 7 be ironed is introduced and removed.

5. An ironing device as defined in claim 2 wherein the means detachably connecting the main portion of said drum, ring elements and end cover members is constituted by bolts.

10 Number Name further includeselectrically heatable resistance elements on said drum for supplying heat to said bands.

8. An ironing device as defined in claim 2 wherein said bands are electrically conductive and adapted to have 5 current passed therethrough for heating the bands.

References Cited in the file of this patent UNITED STATES PATENTS v Date 1,284,668 Haug Nov. 12, 1918 2,618,728 Bram Nov. 18, 1952 

